Flexible shaft



Nov. 15, 1927. 1,649,119

H. A. KJELSBERG FLEXIBLE SHAFT Filed April 26 1925 WITNESSES: INVENTOR ATTORNEY Patented Nov. 15, 1927. UNITED STATES PATENT oFFics.

HARALD AfKJELSBERG, OF WIIiKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTING HOUSE ELECTRIC 8; MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

FLEXIBLE SHAFT.

Application filed April 26, 1923. Serial No. 634,725.

My invention relates to flexible-drive press fit or key at its central portion a. The mechanisms, more especially to a flexiblereduced end portions 5extendlongitudinally drive element associated with electric moof the armature shaft and are journaled by a tors employed where inertia forces are inplurality of outboard bearings 7 constituting a volved, as in electrically propelled railway the end brackets 8 of the motor. 60 ehicles v The bearing members comprise sleeves 9,

It is among the objects of this invention adapted to besecured on ends of the shaft 5 to provide a flexible-drive mechanism which which are further provided with anti-fricshall be of simple, compact structure, and tion bearings 10 of the usual roller or ball- 1 which shall be relatively flexible and capable bearing type which bear against the shoulc5 of absorbing shock and impact which would ders ll of' the shafts 5 and the sleeves 9. otherwise be transmitted to the driving mem- The outer races 12 of the bearings 10 are I secured by a snug fit into the counterbored It is a further object of this invention to portions of the hollow shaft 3 and the inner 1 provide a device of the above-indicated charraces 13 are secured to the reduced ends of 70 actor which shall be adapted to equalize the the shaft 5. Pinion members or gear wheels load or torque at its respective ends to proll or other driving elements, such as cranks, duce equal wear in its respective operating maybe secured at the ends of the shaft 5, parts, outside of the journal bearings 7.

11') Various types of flexible-drive mechanisms In Fig. 2, a shaft 5 having an expanded embodying torsional deflecting shafts have end portion 6 may be substituted for the been proposed, some of which embody yieldshaft shown in Fig. 1 and it may be seing spring elements therein and others concured in the armature shaft 3 and journal sisting of a drive shaft of relatively smallbearings of the motor bracket 8 in a manner diameter secured in such manner as to prosimilar to that described above, the only varia- 80 vide a relatively long extending portion tion being the journaling of the small end 15 which is adapted to torsionally flex under of the shaft in a slightly modified form of l d bracket frame loand securing the expanded My presentinvention is directed to the end 6 on one end of the hollow shaft 3. The

--' latter type of drive mechanism embodying anti-friction bearing 10 is utilized in the t5 one or more torsionally deflecting shaft memsame. manner for supporting the reduced porbers having reduced body portions secured tion of the shaft within the armature shaft 3.

in or to driving members and adapted to en- The operation of this device is briefly as gage drive shaft gears or other driven memfollows: The flexible shaft 5 is driven by the hers at their free ends. I propose to utilize armature 2 of the motor by the press lit or no anti-friction bearing members to support the other manner of mounting at its expanded flexible shafts intermediate their Working portion 6. The torque is transmitted to the ends and their respective supports. gear wheels let, and the flexible shafts by vir- In the accompanying drawing constitutwe of their reduced relatively long body ing a part hereof and in which like reference portions, are adapted to be torsionally flex- 96 characters designate like parts, ible under shock or impact transmitted by Figure 1 is a longitudinal sectional view, the driven members (not shown). The antipartially in elevation, of a flexible-drive friction bearings 10 function to support the mechanism embodying the principles of my shafts 5 at the portion of excessive strain to -16 i mi d eliminate bending and distortion of the same, 1'

Fig. 2 is a similar view illustrating anthe effect of the compound bearings being other embodiment of this invention. to provide a stable drive with an anti-fric- Referring to Fig. 1, the device therein tion support to produce smoothness of opera illustrated comprises an electric motorl contion with the least resistance to the free taining the usual armature 2 that is protorsional flexing of the drive members. 305 vided with a hollow shaft or drive sleeve 3 In the double flexing shaft design illushaving a constricted central portion 4. A trated in Fig. 1, there is an equalizing action flexible shaft 5 having an expanded central between the respective drive gears due to portion 6 is symmetrically disposed within their being actuated from a common source;

" the hollow shaft 3 and secured thereto by a namely, the armature member. In the de- 119 sign illustrated in Fig. 2, the flexible shaft member having a relatively long body portion will provide considerably more flexing than the shorter members of the shaft, Fig. 1, and the particular type to be used will (lee pend on the specific application and operating conditions to which it will be subjected.

It will be obvious, from the above description of my invention, that the flexible drive elements embodied therein provide an cilicient, durable and compact drive mechai'iism which is applicable to a variety of uses but particularly to the driving of electrical railway vehicles where the operating stresses are especially severe and it is es ential to provide a flexible member intern'iediate the driving mechanism and the operating parts.

Although I have described a specific era-- bodiment of my invention, it will be obvious to those skilled in the art that various modifications may be made in the details of construction without departing from the prin ciples herein set forth. iior instance, in general, the motor and armature may be of any suitable construction, and the journal bearings of the flexible shaft members may be designed to adapt the device for specific uses. The anti-friction bearings may be dis posed at any portion of the flexible shaft members or these bearings may be employed in multiple instead of the manner herein illustrated.

I claim as my invention:

1. A flexible-drive mechanism comprising a driving sleeve, a shaft having an ex panded portion secured to said sleeve and journalled at its ends independently thereof and ai'iti-friction beariiigs for supporting said shaft within said sleeve.

2. A flexible drive mechanism comprising a driving sleeve, a shaft having an expanded portion secured to said sleeve and 'journalled independently thereof and anti-friction bearings disposed intermediate the journal and expanded shaft portion for supporting said. shaft within said sleeve.

8. A flexible drive mechanism comprising a driving sleeve, a shaft having an expanded body portion secured centrally of said sleeve and journalled at its free ends independently of said sleeve and anti-friction bearings forsupporting said shaft Within said sleeve.

at. The combination with an electric inotor, of a hollow armature shaft, a torsion ally flexible shaft secured centrally of sai hollow shaft and journalled in the end brackets of the inotor frame and anti-frietion bearings secured at the ends of said armature shaft and adapted to engage the ends of said torsional shaft.

5. The combination with an electric 1notor, of a hollow ari'nature shaft, a flexible shaft having reduced end portions, said flexible shaft being secured centrally of said armature shaft and journalled at its free ends in the end brackets of the motor frame and anti-friction bearings secured at the ends of said armature shaft adapted to retatably support said flexible shaft.

6. The combination with an electric inotor, of a hollow armature shaft, and a {lexibleshaft having a reduced body portion, said flexible shaft being secured at one end in said armature shaft and supported therein at its other end by an anti-friction hearing.

7. The combination with an electric m tor, oi? a hollow armature shaft, and a llexi ble shaft having a reduced body portion, said flexible shaft being secured at one end in said armature shaft and supported therein at its other end, by an anti-friction bearing, said fiexible'shaft being journalled independently of said armature shaft.

8. The combination with an electric inotor, of a hollow armature shaft, and :1 flex le shaft having reduced end portions, said flexible shaft bein secured centrally of said armature shaft and supported therein at its free ends by anti-friction bearirn In testimony whereof, I have hereunto subscribed my name this th day of April. 1923.

HARALD A. KJELSBE 

